cequel_by_key.rb

class Merchant
  include Cequel::Record

  key    :user_id,  :int
  key    :source,       :text    
  key    :source_id,    :text    
  column :name,         :text
  
  # @example
  #   Merchant.by_key(user_id = 1, source = 'facebook', source_id = '4213578641d')
  def self.by_key(*args)
    where(key_column_names.each_with_object({}) { |key, obj| obj[key] = args.shift if args.any? })
  end
end